/*!
 * Ext JS Library 3.1.0
 * Copyright(c) 2006-2009 Ext JS, LLC
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/**
 * @class Ext.tree.ColumnResizer
 * @extends Ext.util.Observable
 */
Ext.tree.ColumnResizer = Ext.extend(Ext.util.Observable, {
    /**
     * @cfg {Number} minWidth The minimum width the column can be dragged to.
     * Defaults to <tt>14</tt>.
     */
    minWidth: 14,

    constructor: function (config) {
        Ext.apply(this, config);
        Ext.tree.ColumnResizer.superclass.constructor.call(this);
    },

    init: function (tree) {
        this.tree = tree;
        tree.on('render', this.initEvents, this);
    },

    initEvents: function (tree) {
        tree.mon(tree.innerHd, 'mousemove', this.handleHdMove, this);
        this.tracker = new Ext.dd.DragTracker({
            onBeforeStart: this.onBeforeStart.createDelegate(this),
            onStart: this.onStart.createDelegate(this),
            onDrag: this.onDrag.createDelegate(this),
            onEnd: this.onEnd.createDelegate(this),
            tolerance: 3,
            autoStart: 300
        });
        this.tracker.initEl(tree.innerHd);
        tree.on('beforedestroy', this.tracker.destroy, this.tracker);
    },

    handleHdMove: function (e, t) {
        var hw = 5,
            x = e.getPageX(),
            hd = e.getTarget('.x-treegrid-hd', 3, true);

        if (hd) {
            var r = hd.getRegion(),
                ss = hd.dom.style,
                pn = hd.dom.parentNode;

            if (x - r.left <= hw && hd.dom !== pn.firstChild) {
                var ps = hd.dom.previousSibling;
                while (ps && Ext.fly(ps).hasClass('x-treegrid-hd-hidden')) {
                    ps = ps.previousSibling;
                }
                if (ps) {
                    this.activeHd = Ext.get(ps);
                    ss.cursor = Ext.isWebKit ? 'e-resize' : 'col-resize';
                }
            } else if (r.right - x <= hw) {
                var ns = hd.dom;
                while (ns && Ext.fly(ns).hasClass('x-treegrid-hd-hidden')) {
                    ns = ns.previousSibling;
                }
                if (ns) {
                    this.activeHd = Ext.get(ns);
                    ss.cursor = Ext.isWebKit ? 'w-resize' : 'col-resize';
                }
            } else {
                delete this.activeHd;
                ss.cursor = '';
            }
        }
    },

    onBeforeStart: function (e) {
        this.dragHd = this.activeHd;
        return !!this.dragHd;
    },

    onStart: function (e) {
        this.tree.headersDisabled = true;
        this.proxy = this.tree.body.createChild({cls: 'x-treegrid-resizer'});
        this.proxy.setHeight(this.tree.body.getHeight());

        var x = this.tracker.getXY()[0];

        this.hdX = this.dragHd.getX();
        this.hdIndex = this.tree.findHeaderIndex(this.dragHd);

        this.proxy.setX(this.hdX);
        this.proxy.setWidth(x - this.hdX);

        this.maxWidth = this.tree.outerCt.getWidth() - this.tree.innerBody.translatePoints(this.hdX).left;
    },

    onDrag: function (e) {
        var cursorX = this.tracker.getXY()[0];
        this.proxy.setWidth((cursorX - this.hdX).constrain(this.minWidth, this.maxWidth));
    },

    onEnd: function (e) {
        var nw = this.proxy.getWidth(),
            tree = this.tree;

        this.proxy.remove();
        delete this.dragHd;

        tree.columns[this.hdIndex].width = nw;
        tree.updateColumnWidths();

        setTimeout(function () {
            tree.headersDisabled = false;
        }, 100);
    }
});